August 2, 2019

expert reaction to the provisional assessment of global average temperature for July 2019, as presented by the European Union’s Copernicus Climate Change Service and the European Centre for Medium-Range Weather Forecasts

Provisional work, presented by the European Union’s Copernicus Climate Change Service and the European Centre for Medium-Range Weather Forecasts, reported that July was the warmest global month on record.

Prof Dann Mitchell, Associate Professor of Atmosphere Science, University of Bristol, said:

“The current global data is showing that this July is probably the warmest on record. Year-on-year myself and other colleagues are reporting these statistics to the media. The warming trend is clear, and the scientific evidence robustly points to this being caused by human induced climate change. A 1.2C increase in global temperature, as reported for this July, almost certainly means an even higher increase in temperature over land, and cities, which are known to warm faster than the oceans. In big cities, this is called the urban heat island effect, and the temperature increase can be 2-4 times the global average. 

“Research shows that many 10s of thousands of people can die prematurely in these heatwaves, and it is often the most vulnerable who are unable to regulate their body temperature well. In parts of Africa this can be a serious problem for mothers and newborn babies. But even in technologically ‘prepared’ nations, such as the UK, this can still be serious. For instance, hospitals are often without AC which can cause problems during heatwaves. Unfortunately, these types of event are projected to get significantly worse in the future, so fundamental infrastructural changes are needed to adapt to our changing climate.”

Prof Richard Allan, Professor of Climate Science, University of Reading, said:

“Months which break the global temperature record, such as July 2016 and June and July 2019, are now the expectation rather than a surprise since this is entirely consistent with the continued increases in atmospheric carbon dioxide caused by human activities.

“Just as one swallow does not make a summer, one record month does not tell us much on its own since the fickle nature of weather systems and the slow sloshing about of the ocean can sometimes temporarily warm or cool the planet. However, the clustering of recent record hot years and months, the longer-term warming trend and our understanding of the physics of the atmosphere and oceans confirms that our climate is heating up, it’s our fault and the way to stop this is to reduce and begin removing emissions of greenhouse gases.”

Dr Karsten Haustein, Environmental Change Institute, University of Oxford, said:

“While July 2019 (as released by Copernicus) virtually equals the global temperature record set for the warmest month on Earth in July 2016, this year’s warm July follows weak El Niño conditions during the preceding winter, whereas strong El Niño conditions were present in 2016. Hence this is yet another reminder that we are on a continuous trajectory towards a warmer planet, driven by relentlessly rising greenhouse gas concentrations in response to unabated emissions. This is also true if July 2019 does not tie with 2016 in other observational datasets (due to be released mid-August).”

The value for July 2019 is a provisional assessment and is the average over the first 29 days of the month. A value for the whole of July 2019 should be available on Monday 5 August.

Declared interests

None received.